An official at Japan's Ministry of the Environment created the group to share mails and documents related to Japan's negotiations during the Minamata Convention, a meeting held in Geneva in January to create international standards to limit international mercury use. But the official used the default privacy setting, leaving the exchanges open to searches and views in the months since. The information has now been removed.

Doh!

So, in essence, not only was the email compromised of anyone who mailed through that network, but all of their communications were available as well.

That's a potentially huge leak because it's like getting a look at the other team's playbook. Their negotiation strategies have been laid bare.